1. Field of the Invention
The present invention is directed to a method for manufacturing a combination of a pressure sensor and an electrochemical sensor
2. Description of the Prior Art
For applications in e.g. medical technology, sensors are used with which a physical quantity can be measured and at the same time chemical determinations (e.g. pO.sub.2 value, pCO.sub.2 value, pH value, electrolyte concentrations) can be carried out. The electrochemical sensor is e.g. an ISFET (ion-selective field effect transistor). Such sensors are described, for example, in European Application 0 465 708 corresponding to U.S. Pat. No. 5,225,063, U.S. Pat. No. 5,376,255 and in the articles of W. Gumbrecht et al., Sensors and Actuators B. 18-19, 704 to 708 (1994), and Sensors and Actuators B1, 477 to 480 (1990). In German OS 44 41 908, the manufacture of thin film pressure sensors on silicon is described, which can ensue in the context of a standard CMOS process technology. Sensors of this sort, manufactured in surface micromechanics, can be monolithically integrated with further components and can be mounted in a housing at low expense. A combination of a sensor of this sort with other components, in particular with electrochemical sensors, is possible by means of modular integration, i.e., the integration of different components on different chips by mounting the components on a common substrate or in a common housing.